Flutter-valve tester



R. M. GRAHAM.

FLUTTER VALVE TESTER.

APPLICATION HLED MAR. 15, 1919.

Pzmmed Feb. 1-5 M 9210 ROBERT M. GRAHAM, OF SIDNEY, OHIO.

FLUTTER-VALVE TESTER.

Specification of Letters Patent.

Application filed March 15, 1919.

Patented. Feb. 15, 1921.

Serial No. 282,989.

(FILED UNDER ACT OF MARCH 3, 18 83, 22 STAT. 15., 625.)

To all 'LU/LOWL it may concczm Be it known that I, ROBERT M. GRAHAM, acitizen of the United States, residing at Sidney, in the county of Shelby and State of Ohio, have invented a new and useful Flutter-Valve Tester, of which the following is a specification.

This application is made under the act of March 3, 1883, (chap. 143, Stat. XXII, p. 625), and the invention herein described and claimed may be used by the Government of the United States or any of its ofiicers or employees in the prosecution of work for the Government, or by any person in the United States, without payment to me of any royalty thereon.

The present invention relates to devices for trying out such articles as flutter valves in order to detect tears, holes, etc.

The usual form of flutter valve as used on gas masks is a modified form of Bunsen valve. It consists of a tube of elastic material open at one end for attachment to the apparatus and closed and flattened at the other end, the flattened end being provided with slits in the edges of the flat-- tened portion. This form of valve has been found to be most efficient and offers less resistance to outgoing gases than any other type and, consequently, is very satisfactory for use with gas masks. It is this particular form of valve that the present apparatus was designed to test.

Heretofore, in testing flutter valves and the like made of rubber or other elastic composition use was made of a horn of suitable material clamped rigidly to a table or bench and the valve or other article placed thereover and stretched to a suitable degree, the holes, or tears, or other defect readily showing in the stretched portion. This method proved to be defective because the operator frequently exerted more pull than necessary and often produced in the testing, holes and tears.

The object of the present invention, therefore, is to prevent the undue stretching of the elastic material but allow sufficient stretching to enable the detection of defects already present.

With this and other objects in view a device, which allows a certain definite predetermined pull to be exerted, was invented.

The present invention, therefore, cm-

prises a suitable horn so arranged that,

upon the exertion thereon of a predetermined pressure, it will be released and prevent the tearing of the article being tested.

In the drawings Figure 1 shows a plan view of the device and Fig. 2 a vertical sectional view with certain of the parts in perspective.

In the device, 1 is a horn of suitable ma terial substantially L-shaped and revolubly supported on a short shaft 2 in a suitable frame work The short arm 4 of this element forms a yoke 5 and through the arms of this yoke is fixed a pin 6.

In the frame-work 3, in the plane of revolution of the element 1, there is a hole 7 and through this hole extends a rod 8 provided with shoulders 9. This rod is also provided with a notch 10, normally fitting over the pin 6, and a beveled end 11 as shown, which end ordinarily abuts against a roller 12 set in the frame parallel with thcshaft 2. The opposite end of rod 8 made sufliciently small to pass freely through the hole 7 and is threaded. for at least a portion of its length as shown at 13. Mounted on this small end. of the rod 8 is a spring 14 abutting against the frame 3 and held in place and under suitable compression by the nuts 15.

In operation, the article to be tested is placed over the rounded end of horn 1 and stretched downwardly, the device being in the position shown in Fig. 2 and held firmly. When sufficient pull is exerted to compress the spring 14:, the rod 8 will move against the roller 12 and in so doing will be lifted by the beveled end 11, thus lifting the notch clear of the pin 6 and releas' ing the short arm l of the horn and allowing the horn to fall.

It will readily be seen that the present device will allow a uniform test to be applied and eliminate any chance of too much stretching of the article.

Having now described my invention and the preferred embodiment thereof, what I claim and desire to secure by Letters Pat ent is 1. In a device for testing elastic articles,

thereby the article being tested from resistance to pull When said horn is subjected to a definite pull.

2. In a device for testing elastic articles, a horn to be engaged by the article, said horn being held in position by compressible 'means and automatic means for releasing said horn and thereby the article being tested from stress and strain when said compressible means is compressed;

3. A testing device comprising a frame, a horn pivotally mounted in said frame, a rod slidably mounted in said frame and provided With means for normally preventing the movement of the horn and means 7 for permitting the movement When pressure upon said horn exceeds a predetermined degree.

l. A testing device comprising aframe having pivotally mounted therein a substantially L shaped horn the short arm of Which is provided With a pin near its extremity, a rod slidably mounted in said frame and provided With a notch for engaging said pin, a spring co-acting With the frame to prevent the sliding of said rod and means co-acting With the rod to disengage the notch from the pin when sufficient pressure is exerted upon said horn to compress the spring.

R; M. GRAHAM 

